Exhibit 21 LIST OF SUBSIDIARIES OF FARMERS & MERCHANTS BANCORP Farmers & Merchants Bank of Central California (incorporated in California) F & M Bancorp, Inc. (incorporated in California) FMCB Statutory Trust I (incorporated in Connecticut) Farmers & Merchants Investment Corporation (incorporated in California), a subsidiary of Farmers & Merchants Bank of Central California. Farmers/Merchants Corp. (incorporated in California), a subsidiary of Farmers & Merchants Bank of Central California.